Centrifugal switch



BEST AVAILABLE COP.

C. R- MARTIN Nov. 23 1926. 1,607,836

CENTRIFUGAL SWITCH Filed April 17 1922 Patented Nov. 23, 1926.

UNITED STATES PATENT OFFICE.

CHARLES R. MARTIN, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CHALMERS MANUFACTURING COMPANY, OF MILWAUKEE, \VISCONSIN, A CORPORATION OF Application filed April 17, 1922. seriai'uo. 553,628.

screw 8 so as to be movable in the plane DELAWARE.

CENTRIFUGAL SWITCH.

This invention relates to centrifugal switches.

One of the objects of the invention is the provision of a centrifugal switch mechanism including a plurality of snap switches. A further object is the provision of such a mechanism in which the snap switches are operable at different speeds. Still another object, is the provision of such a mechanism in which it is possible to adjustably predetermine the speed at which the switches will operate.

-Other objects. will appear hereinafter as 1 tlidescription of, the invention proceeds.

Thenovel features of theinvention will" appear from this specification and the accompanying drawings forming apart thereof and all thesenovel features are intended to be pointed. out in the claims.

- Inthe drawings Fig. 1,is a front elevation ofa centrifugal: switch embodying. the features of the invention, the speed responsive means and its relation .to the switch operating means being shownbut'the switching mechanism being omitted forthe sake of clearness.

Fig.2 is a fragmentary detail view taken in the-plane ofzthe line 11- 111 looking, 1n thedirectionofthe arrows.

. Fig 3 ;.is. a front elevation 6ft 4 switch mechanism of conventional form the operating mechanism.:of -=whichfhas been somewhat modified to adapt for use with the present invention.

v Thecentrifugal swit able rotatable member 1 provided with. an

axially-extending flange 2, formin with the member 1 acylindrical box whic may be provided with a lid if desired. Disposed betweendiametrically opposite points of the flange 2 is a rod 3,.which'may, if desired, be

ch comprises a. suit-j of rotation. One arm of the bell crank is provided with a slot 9 cooperable with a screw 10 passing into the member 4:. The screw 10 is freely slidable in slot 9.

Another bell crank 11 is pivotally mounted on a screw 14 for movement in the plane of rotation and one end of this bell crank is provided with a slot 12 cooperable with a screw 13 passing into member 5. The screw 13 is freely movable in the slot 12.

The other arms of. the bell cranks 11, 7 carry'plates 15, 16, respectively. Plate 15 is plvotally mounted on a screw 17 while plate 16'i's pivotally mounted on a screw 18 which latter also serves to pivotally mount an equal zing rod 19 extending between the bell cranks 7, 11 and pivotally related to hell crank 11 by a screw 20. The'plates 15,

16 may be made angularly adjustable with respect to bell cranks 11,7 respectively, by providing said plates with slots 27, 28 through which screws 29, 30 are adapted to pass into bell cranks 11, 7 respectively. The plates 15, 16 carry projections 21, 22 respectively.

A switch operating means 23 a top view of which may be had in Fig. 2 is provided with 'a slot 24:. i The switch operating means 23, is here, shown-as so disposed that if the projection -21 is rotated a sufiicient amount in a "counter-clockwise direction said projection will enter the hole 24 and upon furtheir movement will move the operating member 23 to efiectively actuate the switch connected therewith] A suitable form of switch is shown in Fig. 3 in order to complete the illustration. The snap switch mechanism here illustrated is of conventional form and it is to be understood that any other suitable form may be utilized. In view of this further description of this snap mechanism is deemed. unnecessary.

Another switch operating member 25 is here; shown disposed with respect to the projection 22 in such manner that when the centrifugal switch is at rest the projection 22 is. disposed in a'transverse hole 26 in member 25. A snap switch mechanism similar to that illustrated inFig. 3 may be connected to the operating member 25.

The operation of the centrifugal switch is as follows: I

Assuming the parts to beat rest, as shown in Fig. 1, and the member 1 to be then set in rotation and: the: speed thereof'gradually increased; -As the speed increases the members 4, 5 will move radially outward, in opposite =direct-ionst- Considering member 4, as this moves-outward, screw 10 will rotate bell crank 7 in a counter-clockwise direction and the projection 22 will move the switch operating member 25 to the right, as viewed in F ig. 1. hen the latter motionhas proceededa predetermined amount, the operating member 25 will have reached the dead-center position of the snap mechanism and when this center is passed the snap switch will be operated. The contacts of the switch operated by member 25 may be arranged, for example, so that a circuit is closed thereby when the parts are at rest and this circuit is opened when the switch is operated'as-hereinbefore described.

As theoutward' movement of members 4, 5 proceeds stillifurth'er with an increase-in speed, the. projection 21', having been moved in a counter-clockwise direction by a bell crank 11, will enter the hole 24; in-switch operating member'2-3 and, upon further movementp will"-' operate the snap switch mechanism connected with member 23" in a manner already. descr bed in connection with member 25;, The switch connected with member 23 may have it's'contacts so arran ed that when operated in the'manner herein hefore described'the circuit controlled thereby will 'be closed:

It is of course to be understood that cur rent maybe le'dto the switches connected? with members23, 25 in anysuitable manner as by slip rings, not"shown. i 1

One of the uses to which thedisclosed centrifugalf switclf'ma-y' beput is in the con-f trol of valvesf for prime' movers, thej'fsp eed' of the prime mover,- heingyariedf'by the se ting;o1'i"th'e 'val've. A The' switch' operatedl'byg member 25 'may, for' exampl, be "connected to a motor which wilI-o'perateto open'a valve of'theprimef-nio verl, As the. speed rises the switclfi 2'5 willib'ej bpened andffylrther opening of the valve will" be stopped. ltthe speed rises a' predetermined additionalamount the switch 23wi11 operate to close the circuit of'the motor to cause the same to operate in a reverse direction to close the vali 'e of'th'e' prime mover;

It should. be understoodthat it is not'desiredto limit the inve'ntioneto' the exact. details of construction shown and described, forvarious modifications may occur to personsskilled in the 'art'.

It is claimed and desired to secure by Letters Patent:

1. In combination, two switches; means associated. with each'ofv said switches to cause each switch to operate with a snap action, a rotatable member, and means including a common actuator for said switches responsive to the speed of said member wherebyas thespeed rises one. ofsaid switches will be operated and as-thespeed rises still further, the other of said switches will be operated.

2. In combination, two switches, means associated with 'each of said: switches to cause each switch to operate with a snap action, a rotatable member, and means including a common actuator for said switches responsive to the speed of said member whereby as the speed rises one of said switches will be opened and as the speed rises still further the other of said switches will be closed.

3. In combination, a rotatable member; at least two snap switches mounted'on' said member, and means including a common actuator for said switches responsive to thespeed of said member whereby-as. the speed rises one of said. switches will be operated and as the speedrises'stillfurtheranother' of saidswitches will be operated.

4. A speed'responsive switch comprising,

arotatable-support, means movable in the" plane of'rotation' and responsive to the speed of saidsupport, ,a switch, means associatedsaid-switch" to cause said-i5 switch to operate with a snap actoin, saidlast-named means being" operatively related to said speed. responsive means and-having'arr operating'member movable in a planesubstantially atright angles tosaid speed responsive means.

5; A speed responsive switch comprising a rotatable support,- two snap switches with' operating. means mounted" on said support, means .res onslve tothe speed of-and mounte'd onsar' supportin operative engagement with one of said snap switches'when-said support is at rest andoperatively engageable with; the-other of said switches at a prede termined speed of said support.

6. In combination-, at least-two switch-es,- means associated with each -of said switches to 'cause eaclr' switch 'tooperate with 'a -snap action, a rotatable member;- and means imeluding a common actuator for said switches responsive to thespeed of said member whereby as the speed risesone of saidi switches will be operated a-nd-- as the speed rises still" further another of saidswitches willbe operated, and; means =-for adjustably predetermining the speed at' whichsecondi named switch will'be operated, P

7 In combination, at least two switches, means associated with each of said switches to causeeachswitch-to operate witha snapaction; a rotatable member, and 'means ineluding a common actuator for said switches responsive to the speed-of said member whereby as thespeed rises one 0f= saidswitchcswill be operated and' as the-speed rises still -further= another ot-said switches will be operated; and-i means -for: adj ustably predetermining the relative speeds at which said switches will be operated.

8. In combination, a rotatable member, at least two switches mounted on said member, and means including a common actuator for said switches responsive to the speed of said member whereby as the speed rises one of said switches will be operated and as the speed rises still further another of said switches will be operated.

9. A speed responsive switch comprising, a rotatable support, at least two switches the inventor is affixed hereto.

CHARLES R. MARTIN. 

